The only changes you can make is to select whether it is being used in a car, truck, bus, taxi...not walking.
Unit actually is rather bulky at about 4 inches or so square and about 2.5 inches thick.
Thanks for the thought though, Patman.
Dave: here's a link to Bizer's site:
http://bizer.com/
then look down the left for GPS info, then click on the bizer.com/garmin link.
Looks like a nice unit. One problem I had with my streetpilot was seeing it in bright sunlight. Hopefully your unit will be better in sunlight. Again..good luck.